Dating your pregnancy
So, that's why Baby Centre, and most health professionals, will be telling you that you've been pregnant for about two weeks longer than you really have been.The due date calculation works best if your menstrual cycle is regular and your periods are every 28 days.Knowing this can help you to be prepared for labour and birth, and to have everything ready for your new baby. Your first pregnancy scan will probably happen when you're between 10 weeks and 14 weeks pregnant.It's known as the dating scan, and is used to give you a more accurate due date, based on the size and development of your baby. You can find out your estimated due date using our handy due date calculator.Some women prefer to count their pregnancy from the day that they were likely to be ovulating during the month in which they became pregnant.Your first ultrasound scan, called your dating scan, will give you a more accurate due date for your baby.The person performing the scan (sonographer) will measure your baby from his head to his bottom.
Find out when your baby is due with our handy pregnancy calculator.Our calculator uses this information to give you an estimated due date.Unfortunately, no one can say for sure exactly when your baby will arrive.Unless you've been tracking your ovulation, there's no way to know for sure exactly when you ovulated and conceived.That's why your due date is calculated based on the date of your last period instead.
If you have an irregular menstrual cycle, you may not know the date of your LMP.